Flask



FIG. 1 is a front, top perspective view of a flask;

FIG. 2 is a front view of the flask;

FIG. 3 is a rear view of the flask;

FIG. 4 is a left side view of the flask;

FIG. 5 is a right side view of the flask;

FIG. 6 is a top view of the flask;

FIG. 7 is a bottom view of the flask; and,

FIG. 8 is a cross-sectional view of the flask, taken along line 8-8 in FIG. 6. 

CLAIM I claim the ornamental design for a flask, as shown and described. 